1. Field of the Invention
This invention relate s to walkers for use by persons needing ambulatory assistance. More particularly, this invention relates to an improved walker having front legs that may be adjusted in length relative to its rear legs to adapt the walker for safe use on irregular and inclined surfaces such as stairs, ramps, steps and curbs.
2. Description of the Prior Art
Alternate or accommodation walkers have been used to provide stability and walking assistance to aged and physically impaired persons. The most used walkers consist of a lightweight, three-sided frame that is self-standing on four legs, which often telescope to adjust the walker's height dimension to conform to the physical characteristics of the user. While such standard walkers provide a stable support when used on flat surfaces, they are highly unstable and unsafe when used on stairs.
This problem is recognized in the prior art and attempts have been made to design a walker that is stable and safe to use on all surfaces. Several such prior walkers are:
______________________________________ U.S. Pat. No. Inventor ______________________________________ 2,708,473 Gable 3,176,700 Drury 3,387,617 Reiber 3,387,618 Swann 3,421,529 Vestal 3,455,313 King 3,800,815 Birk 4,777,973 Nakajima 5,263,506 Narramore ______________________________________
These prior patents disclose various mechanisms for extending or retracting some or all of the legs thereof to adapt the walker for use in ascending or descending stairs. However, none of these references discloses a stair walker having a reliable yet simple and conveniently operable apparatus similar to the present invention for selectively extending and retracting the walker's two front legs.